The buttons for the different tabs on the Activity part of your personal profile page are aligned perfectly fine if you have no recent activity:
but as soon as you have new reputation changes, responses, ..., the line is too wide and the 'votes' button is displayed on the next line. Further, the 'votes' button follows your cursor movement: If you move the cursor over the 'tags' button, you'll see this:
If you move the cursor over the 'answers' button, then 'votes' will be displayed below 'questions'.
I could reproduce this issue with a recent version of Chrome (45.0) and Firefox, both on Win7.
Is this a bug or a feature?